HSOS #19: Creatine, Estrogen & Energy Levels After 40

This episode takes you from Thanksgiving leftovers to midlife muscle science with zero guilt and a whole lot of empowerment. Kim breaks down what creatine actually is, how estrogen decline slows your natural production, and why that’s one big reason your workouts suddenly feel like climbing Mount Everest. She shares the research, the benefits, the side effects, and how she folds supplements into her full-body, full-life functional nutrition assessments so midlife women get exactly what they need to feel strong again. 

Let’s talk. 

Welcome to Her Season of Strength—where women over 40 reclaim their bodies, their energy, and their voices, without apologies. I'm Kim Duffy—registered dietitian, personal trainer, mom, and your biggest hype woman when it comes to aging like you mean it. 

This show isn’t about chasing skinny or counting wrinkles. It’s about building real strength—physical, emotional, and hormonal. Each week, I’ll share straight-talking nutrition tips, sustainable fitness strategies, and conversations that help you feel powerful in your skin once again. 

Menopause is not an ending, it is only the beginning. This is your season of strength.  

 📝 Episode Guide: 

• Thanksgiving stories, food guilt pep talk, and why one day doesn’t undo 364 days of awesomeness 
• Creatine basics: what it is, where it lives, and why it’s basically your muscle’s little energy assistant 
• How dropping estrogen = dropping creatine production 
• Symptoms of low creatine in midlife 
• Research highlights, including women-focused studies  (see references and links below)
• Dosage and timing made simple
• Side effects to watch for, hydration reminders, and who should chat with their doctor before starting 
• How Kim looks at supplements inside an initial nutritional assessment, including labs, symptoms, medications, past history and overall lifestyle 

References:

1. Smith-Ryan, A. E., Cabre, H. E., Eckerson, J. M., & Candow, D. G. (2021). Creatine Supplementation in Women’s Health: A Lifespan Perspective. Nutrients, 13(3).
👉 https://pmc.ncbi.nlm.nih.gov/articles/PMC7998865/

3. Bonilla, D. A., Kreider, R. B., et al. (2024). The Power of Creatine Plus Resistance Training for Healthy Aging. Frontiers in Physiology.
👉 https://www.frontiersin.org/articles/10.3389/fphys.2024.1496544/full

4. Marshall, C., et al. (2025).Creatine and Cognition in Aging: A Systematic Review of Randomized Controlled Trials. Nutrients, 17(1).
👉 https://pubmed.ncbi.nl

Links & resources for this episode:

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Transcript

00:00:00] Hi there, and welcome to her season of Strength, where women over 40 reclaim their bodies, their energy, and their voices, without apologies. I'm Kim Duffy, registered dietician, personal trainer, mom, and your biggest hype woman. When it comes to aging like you mean it, this show isn't about chasing skinny or counting wrinkles.

[00:00:20] It's about building real strength, physical, emotional, and hormonal. Each week, I'll share straight talking, nutrition tips, sustainable fitness strategies. And conversations that help you feel powerful in your skin. Once again, menopause isn't an ending. It's only the beginning. This is your season of strength.

[00:00:39] Hello and welcome back to her season of Strength and if you are new here. Welcome. Welcome, glad to have you. Today I wanna dig into a supplement that has. For women in perimenopause and menopause can really be a life changer because it's something [00:01:00] that, that women don't realize. And when they think of this supplement, they think of 22-year-old Jim Bros chugging, neon drinks out of gallon jugs.

[00:01:09] But it's actually something that can be very helpful for women specifically in perimenopause and menopause. And it is creatine. Here's the thing though, those Jim Bros may be using it, but we actually. Need it more. Okay. Especially during this time in our lives. So I wanna break down what creatine is, what it does, how our natural production of it changes as our estrogen drops, who might benefit from it, what the research says, the benefits and potential side effects.

[00:01:42] All this good stuff, plus how to take it safely because I always look at your whole picture. It's important to look at your history, your labs, your meds, your symptoms, supplements, all of that before taking any kind of a new supplement. So let's dive in. Before I, I jump into that, let's chat a little bit about how the [00:02:00] week has gone.

[00:02:01] Yesterday was Thanksgiving. This is coming out, it'll be a week later, but yesterday was Thanksgiving and all of the food and lovely family time that came with it. And, I hope you all just enjoyed yourself and didn't stress about, oh gosh, I ate a piece of pie, so therefore I need to go and work out or do cardio or in any way, shape or form.

[00:02:23] Feel guilty about the food you ate. Remember, this is just one day out of your entire year. The one day does not make a difference. It's how you spend the rest of the year. It's what are your habits? What are your, what are you doing to help make sure that your body is strong? That one day makes absolutely no difference.

[00:02:44] You might find that you're a, up a pound the next day, that's not a real pound, and you probably add a little more salt than you normally would. You probably have a little more excess water weight than you normally would, but don't stress about that. Enjoy yourself, enjoy your family, enjoy this good, delicious [00:03:00] food, but make sure that those habits that you are doing, those other 364 days during the year are solid.

[00:03:07] All right? And that's why if you, any of you heard. By the time that this comes out, my Stronger, Not Softer Holiday Planwill be in the works. It starts December 1st, and the reason why I created that was because I want women to feel good rather than just dredging your way through the holidays and feeling like crap at the end of it.

[00:03:31] Because you have just thrown aside your exercise, you've thrown aside your good nutrition. Because you feel some kind of guilt or some kind of way about how you're eating or the holidays. Oh, just throw 'em to the wind. I have parties, I am drinking more than I normally would.

[00:03:47] I'm eating more than I normally would, so therefore I am gonna just forget about everything I've done the rest of the year. And then what happens is we get to January one and that's when we're feeling like we need [00:04:00] that reset. We need that restart because. Over, the previous six weeks, we've just undone our normal, right?

[00:04:07] So you're feeling like you need to just kind of restart. So that's why I created that this holiday plan is just something, no guilt, no shame, but how can we stay strong and can consistent throughout these six weeks that can cause such chaos. In our typical routines and in our life. So anyway, when this comes out, my my first week will be in full swing, so I'm super excited.

[00:04:31] This is a new program. I just created it this year for kind of a Black Friday deal, just to help women get through the holidays in a positive way. So first, now let's, start with the basics of creatine. Let's take a deep dive, creatine. Is naturally occurring in your body and it's stored mostly in your muscles.

[00:04:53] And a good amount of it is in your brain. Its whole job is to help our body to regenerate [00:05:00] that quick burst energy source called a ATP. I promise this isn't gonna be like this really heavy science laden podcast, but I do want you to understand the basics. So a ATP is adenosine tri phosphate, right?

[00:05:13] So it's that quick burst energy source in our body. You think about lifting weight, sprinting, pushing something heavy, or even getting up off the floor in one smooth move. All these things we need a ATP. So what here is one thing that, that most women don't realize, but our bodies actually create creatine on its own.

[00:05:30] Our liver, kidneys, pancreas, take three amino acids called arginine, glycine, and methionine, and convert them into creatine. A healthy woman usually makes about one to two grams per day, and you're also gonna get a little creatine from food. But unless you're eating red meat or fish daily, you're not getting all that much.

[00:05:51] Here's where things get really interesting for us in midlife. Estrogen helps to support creatine synthesis or the making of creatine. So [00:06:00] when our estrogen drops in perimenopause and menopause, our natural creatine production drops too. And that has some ripple effects. So when creatine levels decrease, you might notice that your muscles fatigue faster or easier.

[00:06:13] Your workouts feel harder than they should. Recovery takes a little bit longer. We don't see as much of those strength gains. They slow down and we feel less powerful both physically and mentally. Brain fog or mental fatigue becomes more common. And that's, we know that's related to a lot of different things.

[00:06:35] Our motivation feels, not quite as boisterous as it was before. To put it nicely, right? And our energy levels feel inconsistent or lower. So that's why when women tell me, Kim, I'm doing the same workouts I did a year ago, and everything suddenly feels harder, creatine is one of those things that I am gonna consider and have a discussion with my client about.

[00:06:57] And it's not because the workout has [00:07:00] changed, your physiology has changed, right? As your natural levels dip. Supplementation can simply fill that gap that our body doesn't produce as easily anymore. So now that we know what creatine actually is and how our own production shifts in midlife, let's talk about why this matters so much.

[00:07:19] For women our age. So this season of life it comes with just natural muscle loss. We see that muscle declining. We see our strength declining. We see that we're more tired. We start to see that we have those shifts in cognition. A little more brain fog, difficulty with memory. And it changes in how we recover as well.

[00:07:38] So creatine plays a role in nearly all of these areas because creatine helps us to regenerate energy inside of our muscles, women who are losing estrogen and the muscle protective benefits that estrogen gives us, right? We feel the drop more intensely. Because creatine can help support our lean muscle mass, our strength, [00:08:00] our power, and then also that explosiveness, so that the exercise of we go from standing still to maybe running or jumping functional movement too.

[00:08:09] Even just like walking up the stairs or lifting something from the floor or getting up off the ground. Creatine can also help us to recover faster when it comes to exercise. Maybe have a little bit less fatigue around exercise and then can also give us that support cognitively. Help us a little bit with memory, with mental energy and with concentration.

[00:08:32] So this is one of the reasons that when I see clients. During their initial assessment, I'm gonna talk to them about all the different reasons why they might be feeling more fatigue. They might be, seeing more muscle loss, struggling with recovery or feeling mentally or cognitively flat.

[00:08:51] And creatine is part of that conversation along with what are your current lab values, making sure we don't have any vitamin or mineral deficiencies that [00:09:00] we need to supplement. Looking at your full Nutritional intake, to see if there's any areas that you're missing or that we need to be filling in, or even absorption.

[00:09:11] Maybe your body is, you're eating very well, but maybe your body isn't necessarily absorbing things like it should. But these are all things that I talk about to women. In that initial nutritional assessment, just to get that full picture of everything going on with them, that's called, functional nutrition.

[00:09:29] You look at that root cause. Of, of some of these symptoms and some of 'em aren't as clear cut as one thing causing them. So let's nerd out for a minute because the research behind creatine is some of the strongest in sports and nutrition science. Here's a few highlights. So creatine consistently increases strength, power, and lean muscle in women, especially when it's paired with strength training.

[00:09:54] There's a strong evidence for benefits in cognitive or your brain health, in [00:10:00] specifically in relation to memory, reaction time, and reducing mental fatigue. Some research shows that creatine may help protect bone health indirectly by improving muscle strength, which is gonna decrease risks of falls and fractures.

[00:10:16] There was a two, two, sorry. There was a 2022 review specifically looking at creatine and women during perimenopause and menopause, and found improved muscle function, increased strength and performance, and the International Society of Sports Nutrition. Nutrition actually calls creatine one of the safest, most effective supplements available.

[00:10:39] And at one point I, I did study sports nutrition specifically. I was working at a lifetime nearby where I live for a little while. And so I got my sports nutrition certification and I can always remember that. They called creatine an ergogenic aid and they were looking at it specifically, more often than not at these [00:11:00] men who were lifting weights and finding, oh, it can really be beneficial in decreasing soreness after a workout and helping your muscles to pull in fluid to help them recover.

[00:11:10] Better after a workout. And what's interesting is they didn't, have a lot of research and studies for women, but nowadays they're doing so much specifically around perimenopause and menopause. And I'm gonna link some of these studies that I talked about in my show notes so you can di dive deeper if you love the science as much as I do.

[00:11:29] If not, take my word for it, okay, so now let's talk a little bit about dosage and timing. Creatine dosing is simple. You don't need loading phases or any fancy formulas, especially for women. The most research dose is three to five grams of creatine, monohydrate daily. Okay. And you wanna make sure you're getting it from a good source.

[00:11:49] I really like the Thorn brand. It's a good quality brand. Third party tested. So that because with supplements they aren't regulated like medications. So [00:12:00] we need to make sure we're going with good quality supplements so that we're not questioning. If they truly have in them what they say they have in them.

[00:12:09] That's the big problem is if they're not third party tested by somebody who is non-biased and say, yes, we tested this product and it has in it what its label or what that label says that it has in it. It's hard to really know truly. If it does, so few quick notes about this says timing doesn't matter.

[00:12:28] You can take it when you'll remember to take it. I actually, for some reason I'll take it before my workouts. But you don't necessarily empty. You can put it in your water, your juice, your coffee, you can put it in a smoothie. Whatever works. It dissolves best in warm water or even like hot coffee.

[00:12:44] It's not a stimulant, so you don't have to worry about it having a load of caffeine in it, and most women will feel the difference within two to four weeks. So it's not necessarily something you're gonna take one time and go, oh my gosh, I feel amazing. This is great. I remember I started taking it when I [00:13:00] was in my early fifties because I was having.

[00:13:05] Some hip pain, some hip, joint kind of issues. And granted, I was doing all my hip mobility work and exercises, stretching, foam rolling and all those things. And so I thought, you know what? I'm gonna try this creatine. And I started taking that and literally within two to four weeks I did find that hip discomfort.

[00:13:25] Was less now, I am not, I am not gonna be the person that tells you, take this one supplement and it is going to make everything better for you. But I am a proponent of taking these kind of things more natural as compared to jumping to a medication or taking a Tylenol or an Advil or something that's gonna reduce the pain and cover up that symptom without really truly getting to what's the cause of it.

[00:13:51] Okay, so let's talk about the specific benefits that you might find and you can watch for, maybe you journal. Once you take creatine, it's gonna [00:14:00] help to build strength. This isn't gonna be a matter of, I take it once and I'm gonna go from lifting 10 pound dumbbells to 40 pound dumbbells.

[00:14:09] But it's gonna be, it. It can actually help with building muscle, it can help with recovery. After a workout, maybe you're a little bit less sore. Maybe your muscles adapt quicker and easier. After you strength train, you might notice that you have a little bit of an improved performance or stamina or endurance.

[00:14:28] Can help with brain and that, that cognition, and you might find that it helps a little bit with more consistent energy, common side effects. Let's talk about these for just a second. You might find that you have temporary wa, excuse me, water retention in the muscle. This is not bloat. This is not fat gain like I was telling you.

[00:14:47] That's how it helps with that recovery is it can pull in a little extra fluid into those muscles that is temporary. It goes away. Some people notice that it gives mild stomach discomfort if you [00:15:00] take too much at once. You should not notice this with three to five grams per day or multiple times a week.

[00:15:07] And then you might find you have a slight weight increase temporarily on the scale, specifically from that water retention. And hydration matters. Make sure that if you are taking creatine, make sure you're getting in plenty of fluids to help flush it. And safety note, let's talk about creatine is safe for healthy individuals, but if you have any kind of kidney disease or kidney issues or you're elevated kidney labs, if you are have any kind of uncontrolled medical conditions or you're on certain medications, talk to your doctor first.

[00:15:39] Okay? I am not. Diagnosing. I am not, telling you to start the supplementation. I'm just giving you the risks, the benefits, and some of the research behind it. Okay? This is why I always review supplements, medications, labs, and symptoms during that initial nutritional assessment that I do with a client is because I, no supplement is a one [00:16:00] size fits all.

[00:16:00] It's not like I'm just gonna, over everybody. Hey, everybody start taking this, but. It's one of those things that I say maybe take it for one to two months and then see if you notice a difference. See if you notice a benefit. Sometimes what I find funny is that you might go, oh, I can't really, I can't really tell if it's really doing anything, and then you'll go off of it and that's when you'll notice that it was doing something that some of those symptoms might come back.

[00:16:25] Okay. So let's chat a little bit about who might benefit most from this, if. You're a woman in perimenopause or menopause, if you have noticed that you have more fatigue than typical, if you are strength training consistently, and that would mean, if you're getting in your strength training two to three times a week or more.

[00:16:46] If you are working to try to build or maintain muscle or strength, which hey, all of us, every single one of us should be doing that or working towards that. If you notice that recovery is slower. Maybe you're [00:17:00] sore for a longer period of time. Not wanting to get in another workout too quickly, feeling more tired if you're struggling with motivation or brain fog.

[00:17:11] If you are a vegetarian or a vegan, now you might have even more benefit from the supplementation because you aren't getting it from those animal sources. If you recognize, if any of these things go, oh yeah. Creatine could be potentially a supportive tool for you. And it's not a magic pill like any vitamin mineral or herbal supplement.

[00:17:35] It is not a magic pill, but it is one of the most researched, effective and safe supplements that we have. And the benefits for women in midlife are real. And if you are working towards wanting more strength, if you want more energy, if you want to, to see if it might help you with better workouts or help a little bit with cognition or brain function, it might be worth exploring.

[00:17:59] And if you [00:18:00] wanna help figuring out what's right for your body, that's exactly what I do during a initial nutritional assessment. So you can  look at your whole picture, we look at your medical history, your symptoms, your labs, your medications, your goals, so that you can get support that fits you where you are, exactly where you're at.

[00:18:18] So if this episode has helped you, please share it with another woman in midlife who needs it. I would love if you could leave a quick rating or review. It means the world and it helps more women to find this show. And message me anytime if you have any questions or takeaways. 'cause remember, it's about progress over perfection.

[00:18:36] We're in this for the long haul and this is your season of strength. Have a fantastic day.